1. Field
The present disclosure relates generally to hearing assistance devices such as, for example, implantable cochlear stimulation (“ICS”) systems and hearing aids.
2. Description of the Related Art
A wide variety of hearing assistance devices are available. Such devices include, but are not limited to, ICS systems and hearing aids.
ICS systems are used to help the profoundly deaf perceive a sensation of sound by directly exciting the auditory nerve with controlled impulses of electrical current. Ambient sound pressure waves are picked up by an externally worn microphone and converted to electrical signals. The electrical signals, in turn, are processed by sound processor circuitry, converted to stimulation data (e.g., a pulse sequence having varying pulse widths and/or amplitudes), and transmitted to an implanted receiver circuit of the ICS system. The implanted receiver circuit is connected to an implantable electrode array that has been inserted into the cochlea of the inner ear, and electrical stimulation current is applied to varying electrode combinations to create a perception of sound. Alternatively, the implantable electrode array may be directly inserted into the cochlear nerve without residing in the cochlea.
Referring to FIG. 1, conventional ICS systems commonly include an implantable device 11 and an external sound processor 12 with a housing 14, sound processor circuitry 16, a microphone 18 that is in communication with the sound processor circuitry, and a battery or other power supply 20. In the type of ICS system illustrated in FIG. 1, the sound processor is worn behind the ear (a “BTE sound processor”) and includes an earhook 22. The sound processor 12 transmits stimulation data, as well as power from its power supply 20, to the implantable device 11 by way of an inductive link. To that end, ICS systems include a headpiece 24 that is connected to the sound processor 12 by a cable 26. The headpiece 24 has a coil antenna that is used to connect the headpiece (and BTE sound processor by way of the headpiece) to the implantable device via an inductive link. So configured, the BTE sound processor provides sound processing functionality and also provides power for the entire ICS system. A representative ICS system is disclosed in U.S. Pat. No. 5,824,022, which is entitled “Cochlear Stimulation System Employing Behind-The-Ear Sound processor With Remote Control” and incorporated herein by reference in its entirety. Examples of commercially available ICS sound processors include, but are not limited to, the Advanced Bionics™ Harmony™ BTE sound processor. Other ICS systems are configured such that all of the external components (e.g., the battery, the microphone, the sound processor, and the coil) are carried within a single headpiece. One example of such a system is disclosed in U.S. Pat. Pub. No. 2010/0046778, which is entitled “Integrated Cochlear Implant Headpiece” and incorporated herein by reference in its entirety.
Hearing aids include a microphone, sound processor circuitry, and a speaker (sometimes referred to as a “receiver”). Here too, ambient sound pressure waves are picked up by the microphone and converted into electrical signals. The electrical signals, in turn, are processed by sound processor circuitry. The processed signals drive the speaker, which delivers amplified (or otherwise processed) sound pressure waves to the ear canal. Exemplary types of hearing aids include, but are not limited to, BTE hearing aids, receiver-in-canal (“RIC”) hearing aids, and in-the-canal (“ITC”) hearing aids. Examples of commercially available hearing aids include, but are not limited to, the Phonak™ Ambra™ hearing aid and the Phonak™ Naida™ hearing aid.
The present inventors have determined that conventional ICS systems are susceptible to improvement. For example, the present inventors have determined that some patients would benefit from an ICS system with an external sound processor that is smaller and lighter than those currently available and that this may be accomplished by altering the manner in which power is stored and supplied within the ICS system.